Considerable information is now available concerning the conditions in which age-related memory losses occur in human subjects. In addition studies conducted within the human information processing framework have made significant advancements toward our understanding of the mechanisms underlying these processes, namely storage, maintenance and retrieval properties. An ultimate goal of this research is to determine the circumstances and/or conditions by which age-related memory declines can be alleviated. One promising area directed toward this goal is the administration of psychopharmacological agents which enhance retention capabilities. Further progress in this area critically depends upon an animal model of aging and memory which closely parallels the conditions and concepts formulated for human subjects. A major aim of the present proposal is to determine the conditions and mechanisms responsible for age-related forgetting in Fischer 344 rats. Several paradigms will be tested which are known to produce forgetting in adult rats using both short-term and long-term memory paradigms. Susceptibility to forgetting in these paradigms will be assessed across age groups, and determinations will be made concerning the factors responsible for retention loss, contextual cues, internally-generated cues, and/or sequential information. In addition two studies will use a reactivation technique to determine if the differential forgetting observed in aged rats is a function of storage or retrieval failure.